code: def forward(self, x_start, t, noise=None):
      noise = default(noise, lambda: torch.randn_like(x_start))
      return (
          extract_into_tensor(
              self.sqrt_alphas_cumprod, t, x_start.shape
          )
          * x_start
          + extract_into_tensor(
              self.sqrt_one_minus_alphas_cumprod, t, x_start.shape
          )
          * noise
      )
  
file_path: NeMo/nemo/collections/multimodal/models/text_to_image/dreambooth/util.py
imports: from functools import partial
  import numpy
  import torch
  import torch.nn
  from nemo.collections.multimodal.modules.stable_diffusion.diffusionmodules.util import extract_into_tensor, make_beta_schedule
  from nemo.collections.multimodal.parts.stable_diffusion.utils import default, exists
  from nemo.core.classes.common import Serialization
label_desc: Use image node_id 3 for calling the sd_noise_scheduler obj's underlying member method code with example usage: obj.forward(x_start, t, noise) and returns: unknown